(i) Field to Which the Invention Relates
The present invention is with respect to a windsurfing board with a surfboard-like hull, a mast joined to said hull by a universal joint, a sail, a spar for winging out said sail, and at least on a stern part of said hull stabilizing faces on the two sides of said hull, said stabilizing faces being generally horizontal when viewed in a direction normal to the median line running through the middle of the hull.
(ii) The Prior Art
Such a windsurfing board hull has been put forward in the past, see for example German Gebrauchsmuster Pat. No. 7,924,335, in which case horizontal stabilizing fin plates are placed to the two sides of the stern and forming a single structure therewith so that in the unloaded condition of the hull they are to be over the waterline. The hull of the windsurfer is V-like in cross-section at the fore end with the point of the V running downwards while in the middle part of the hull, the hull's lower face is convexly curved downwards and in the stern part it is convexly curved between the generally horizontal stabilizing faces. The purpose of this form of the hull of the known surfing board is that of increasing stability, more specially when sailing before the wind without increasing the wetted surface, because this would make for a decrease in speed.
It is known in the art that windsurfing board of the displacement type are faster than other windsurfers when the wind is low and that, when sailed in a strong wind, are slower because windsurfing board without such fin plates go over into the planing condition more readily and earier, such a planing condition making it possible for the hull to be sailed at a much higher speed than would be possible, in theory, if the hull is simply sailed as a displacement hull.